This invention relates to a surgical appliance for the fixation of fractured bones and, more particularly, to an extramedullary surgical appliance which, when in use, exerts a desirable compressional force on the segments of the fractured bone.
Various devices are known for use in setting fractured bones. One type of device is described in U.S. Pat. Nos. 3,374,786 and 3,996,931, both issued to G. R. Callender. This device is particularly adapted for the fixation of fractured bone segments in a femur. A trochanteric plate is secured to the upper segment of the femur by means of surgical screws, this plate being provided with a sleeve member attached thereto at an appropriate angle. The upper segment of the femur is bored to receive the sleeve member and also to receive an elongated shaft having a screw portion, which shaft is embedded within the femoral head by means of the surgical screw portion. An adjustable limit screw assembly serves to retain the shaft member within the sleeve member. The sleeve member carries a key which is insertable into grooves of different lengths on the shaft member, depending upon the type of fixation which is desired. Axial compression is provided by adjusting the limit screw assembly.
Unfortunately, the device of the type described in the aforementioned Callender patents is limited solely for use in the fixation of a femur. Because of the particular angular displacement of the sleeve member relative to the plate member on which it is formed, this device cannot be used in other bones, particularly the humerus bone. Also, the device described in the Callender patents is relatively complex and, accordingly, is accompanied by relatively high manufacturing costs. Still further, it is somewhat difficult to use. Moreover, since the throchanteric plate and the shaft member must be embedded into the femur, it is difficult to use this device in combination with other, conventional fixation devices, such as surgical pins or screws, in the event of a three-part fracture, or other multiple fracture, of the femur.
Another type of surgical appliance which has been proposed for the fixation of fractures is described in U.S. Pat. No. 1,997,466, issued to E. E. Longfellow. This device consists of a pair of skeletal pins which are inserted through the bone on either side of the fracture, which pins extend from the injured limb. Turnbuckles are secured to opposite ends of the pair of pins and are suitably tightened so as to exert a compressional force on the fracture. However, since the pins extend externally of the injured limb, and since the turnbuckles must be secured at the extreme outward ends of such pins, there is the danger of infection. Also, in the event of an inadvertent blow or force imparted to the turnbuckle assembly, the injured limb can be further damaged. Still further, the overall appliance is relatively bulky and unwieldy for the patient, thus adding to his discomfort. In addition, the device is not easily usable by the surgeon.
A device which has been proposed for correcting certain forms of physical deformity by exerting compressional forces onto selected vertebrae is described in U.S. Pat. No. 3,997,138, issued to H. V. Crock et al. In this device, a pair of surgical screws are embedded into the vertebrae. Each screw includes a head containing channels through which rods are passed. A caliper, formed of a pair of levers, is used to urge the surgical screws, which are embedded into the vertebrae, either closer together or farther apart. When the proper relative position of these screws is attained, the rods which link the screws are clamped thereto, and then the caliper is removed. Thus, the position of the screws, and thus the vertebrae, is fixed.
While this device might be suitable for correcting certain physical deformities, the fact that a caliper is required to position the surgical screws results in a complicated procedure whereby the device is not suited for the fixation of fractures. Furthermore, the caliper which must be used with the surgical screws is quite expensive, in and of itself.
Accordingly, there is a need for a surgical device for the fixation of fractured bones which is relatively simple to manufacture and to use, yet which is adapted to exert desirable compressional forces on the fracture. Also, there is a need for such a surgical device which can be used in conjunction with other fixation devices, such as other intramedullary devices, or can be used with extramedullary devices.